Logging Evaluation Study on Water-Flooded Zones in Key Adjustment and Management Blocks of Huabei Oilfield

After over 40 years of development, most oilfields in the Huabei Oilfield have entered the high water-cut stage. Due to the variable properties of injected water and the influence of reservoir lithology and physical properties on waterflood front advancement, the logging evaluation of water-flooded zones has become increasingly challenging. In response to the growing prevalence of water-flooded zones in high water-cut blocks, this study employs nuclear magnetic resonance (NMR) and array induction logging technologies. Through analyzing the logging response characteristics of water-flooded zones, it clarifies the relationship between array induction resistivity changes and water-flooding degree as well as reservoir pore structure after oil layer flooding, along with the variation features between water-flooding degree and NMR T2 spectrum. Based on these logging response characteristics, a graded interpretation standard for water-flooded zones is established to enhance logging interpretation accuracy. This effectively addresses the logging interpretation challenges of water-flooded zones in adjustment wells for old oilfield management blocks, providing technical support for comprehensive remediation of mature oilfields.